Process of separating chalcocite ore



Patented Mar. 31, 1942 2,278,020 PROCESS OF SEPARATING CHALCOCITE ORE Anderson W. Ralston and Erwin W. Segebrecht,

Chicago, Ill., assignors to Amour and Qompany, Chicago, 111., acorporation oflllinois No Drawing. Application November 3, 1939, Serial No. 302,762

\ that the primary amines behave very much dif- 6 Claims.

This invention relates to the separation of copper sulfide from chalcocite ores containing the same, and it comprises processes wherein the chalcocite ore is subjected to froth flotation in the presence of a flotation agent comprising a water-soluble salt of a primary aliphatic amine having at least six carbon atoms.

One of the more important ores subjected to froth flotation for the separation of metalliferqus values therein is a copper sulfide ore known as chalcocite. This ore contains copper in the form of copper sulfide often associated with lead, zinc and iron sulfides, and a siliceous gangue usually.

in the form of quartz. Although many different flotation agents have been suggested for use in the processing of such an ore, none of the agents hitherto used have been satisfactory in all respects. In the first place, it is absolutely essential that the agent be relatively inexpensive when figured on a cost-per-ton of ore treated basis. If the agent is expensive when bought by the pound the quantity of agent used should be very little in order to balance the high initial cost of the agent. In the second place, the flotation agent should be highly selective so that most of the copper sulfide is concentrated in either the tailings or the concentrate as the case may be.

We have now discovered that the water-soluble salts of primary aliphatic amines having from six to eighteen carbon atoms are particularly fine flotation agents for separating copper sulfide from siliceous gangue in chalcocite-containing ores. And we have discovered that whether an amine or an amine salt is better for use in the general separation of ores depends largely on the mineral to be separated. We have ascertained that the amines and amine salts are not in general equivalent. In some instances the amine salt is a very much better flotation agent; in other instances the amine is preferable. Occasionally a both the aminesand the water-soluble salts are equally eflicacious, but this depends entirely on the ore subjected to the flotation.

In the present application we have discovered that the primary amine salts work very much better than the primary amines themselves. our co-pending application filed of even date herewith, and wherein we describe the separation of copper pyrites (CuFeSz) from gangue minerals, we have discovered that both the amines and the amine salts work equally well. In certain other applications we have described the use of the primary amines themselves as flotation agents for the separation of the constituents in a phosphate ore. In that case we have discovered ferently from the amine salts, not only in respect to the efficiency of the separation process, but in respect to the results obtained. That is to say, when phosphate ores are floated in the presence of a primary amine it is a siliceous gangue which appears in the concentrate and the phosphate appears in the tailings.

In the process of the present invention the siliceous gangue appears in the tailings and the copper sulfide floats.

In order that our invention may be more thoroughly understood, we shall now give an example of how it may be practised. A chalcocite ore containing 39.81% of copper sulfide and 49.55% of SiOz was subjected tofiotation in the presence of dodecylamine acetate. 0.1 lb. per ton of this flotation agent was used with the ore, the aqueous ore pulp having a pH of 5.1. About 494.64 parts by weight of chalcocite were used in the flotation cell and subjected to flotation in I the presence of the amine salt. Froth flotation resulted in a concentrate weighing about 250.11 parts by weight and the tailings amounting to about 244.53 parts by weight. The composition of the concentrate was as follows: SiOz 5.0%, CuS 74.25%. The tailings contained 93.90% of S102 and 3.91% of CuS. 2

Based on the above analysis the separations were as follows: SiO2 94.44% in the tailings and 5.56% in the concentrate. There was 95.09% of copper sulfide in the concentrate and 4.91% in the tailings.

.obtained when other water-soluble salts of dodecylamine are used, such, for example, as the hydrochloride. Likewise, other primary amine salts can be used. Hexylamine acetate, octlylamine acetate, decylamine acetate, tetradecylamine acetate and octadecylamine acetate behave very much better than the corresponding amines. We find that dodecylamine acetate and dodecylamine hydrochloride shows the greatest selectivity but the other amine salts enumerated as well as the corresponding hydrochlorids', can be used.

The present invention is restricted to the separation of copper sulfide from ores containing chalcocite. As stated, in our co-pending application filed of even date herewith, we described separation of copper pyrites, namely copper iron sulfide, from ores containing chalcopyrite. It will, of course, be understood that our invention is practised in precisely the same wayas other flotation processes. Consequently, we have not described the flotation separation itself in detail.

Having thus described our invention, what we claim is:

1. In the separation by froth flotation of copper sulfide from chalcocite ores the step which comprises subjecting an aqueous pulp of the chalcocite ore to froth flotation in the presence of a water-soluble primary aliphatic amine salt having from six to eighteen carbon atoms.

2. In the separation of copper sulfide from siliceous ores containing the same the step which comprises subjecting the ore to froth flotation in the presence of a water-soluble primary aliphatic amine salt having at least six carbon atoms.

3: The process as in claim 1 wherein the amine salt is a water-soluble amine acetate.

4. :Ihe process as in claim 2 wherein the amine salt is a water-soluble amine acetate.

5. The process as in claim 1 wherein the amine salt is dodecylamine acetate.

6. The process as in claim 2 wherein the amine salt is dodecylamine acetate.

ANDERSON W. RALSTON. -ERVIN W. SEGEBRECHT. 

